This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This research is studying brain structure and function in children who were born prematurely and received erythropoietin [Epo] during their hospitalization, compared to those who did not, and compared to children who were born at term [born around their due date]. Children born prematurely are at great risk for brain injury and resultant poor brain growth, early developmental problems, and school delay. The purpose of this research study is to determine if Epo, a medicine that helps the body make red cells, can also improve a child's brain growth and mental development. In addition to its ability to stimulate red cells to grow, Epo has been evaluated because it may protect the brain from injury. This study will look at both brain growth and development. First, the study will compare brain growth of children who received Epo during their initial hospitalization to children who did not receive Epo, using a magnetic resonance imaging [MRI] scan and a magnetoencephalography [MEG] scan. Second, the study will evaluate the level of development in these two groups using special developmental tests designed for children. For comparison, children who were born at term will also be evaluated for brain growth and development.